As the demand increases for varying types of applications within mobile telecommunications networks, service providers must constantly upgrade their systems in order to reliably provide this expanded functionality. What was once a system designed simply for voice communication has grown into an all-purpose network access point, providing access to a myriad of applications including text messaging, multimedia streaming, and general Internet access. In order to support such applications, providers have built new networks on top of their existing voice networks, leading to a less-than-elegant solution. As seen in second and third generation networks, voice services must be carried over dedicated voice channels and directed toward a circuit-switched core, while other service communications are transmitted according to the Internet Protocol (IP) and directed toward a different, packet-switched core. This led to unique problems regarding application provision, metering and charging, and quality of experience (QoE) assurance.
In an effort to simplify the dual core approach of the second and third generations, the 3rd Generation Partnership Project (3GPP) has recommended a new network scheme it terms “Long Term Evolution” (LTE). In an LTE network, all communications are carried over an IP channel from user equipment (UE) to an all-IP core called the Evolved Packet Core (EPC). The EPC then provides gateway access to other networks while ensuring an acceptable QoE and charging a subscriber for their particular network activity.
The 3GPP generally describes the components of the EPC and their interactions with each other in a number of technical specifications. Specifically, 3GPP TS 29.212, 3GPP TS 29.213, and 3GPP TS 29.214 describe the Policy and Charging Rules Function (PCRF), Policy and Charging Enforcement Function (PCEF), and Bearer Binding and Event Reporting Function (BBERF) of the EPC. These specifications further provide some guidance as to how these elements interact in order to provide reliable data services and charge subscribers for use thereof.
For example, 3GPP TS 29.212 and 3GPP TS 29.214 provide some guidance on the establishment of an application session by the EPC upon receipt of an application request from an application function (AF) in the form of an AA-Request (AAR) message or from a packet data network gateway (PGW) in the form of a Credit Control Request (CCR) message. The standards specify that the PCRF is responsible for receiving new application requests, creating new policy and charging control (PCC) rules commensurate with such requests, and providing these new PCC rules to the PCEF for installation. The 3GPP standards also define the format of application request messages and PCC rules.
According to the 3GPP standards, activation and deactivation times can be used to determine when a PCC rule is active and when the PCC rule is inactive. However, different versions of the relevant specification may be in use by different PGWs in an LTE network and these versions may specify different behavior with regard to PCC rule activation/deactivation times and how such times are specified. Furthermore, some of the related time dependent behavior could be optional. Due to the variations in behavior resulting from these differences and/or optional behavior, it is difficult for a PCRF node (PCRN) to support PCC rule activation and deactivation with multiple PGWs. Other PCRN actions may also depend on the time of day.